Just a quick note on the offer you linked.
Not sure the base with the transmitted light on the MX-3 is worth the extra money. Looking at invertebrates I've never missed such. But for plants it may be more helpful ?
Like Paul mentioned, keep some budget for (an) extra reflective light source(s). The professional fiber optic thingies usually cost as much as the microscope, but I feel today that there are decent enough alternatives with high power LEDs. These emit more heat than the fiber optics (main reason for using those), but a lot
less than the "old school" direct lights that made the fiber optics a must have (by penalty of melting/shriveling your specimen). I fare well enough with one or two "Jansjö" LEDs on a swan-neck from our local Swedish furniture supplier.
Also like Paul mentioned - have a hand-lens for low magnifications, then use the binoc to do better.
You will soon find that you will want to switch forth and back between lower and higher mags. I have never worked with the system, but imho the MX-1 to MX-3 displayed would soon make me cuss - having to slide in a different objective (or set of eyepieces) will almost certainly disturb/move your target (or it will simply walk away meantime, if life specimen). Also, you would need to buy the extra objective/eyepieces (which adds to the cost!), so I would strongly advice for a model with at least two magnifications in a turret such as the MX-4T or MX-5T, which are incidentally cheaper that the one you eyeballed. Or better yet, a "zoom" model, but that will be above budget.
Silly thing with those 4T/5T apparently is that you can't change the eyepieces at home
So make a smart choice when ordering.
10x won't give you much above a hand-lens (except for comfort). I have a Olympus with 20x/40x mag (1x/2x turret with 20x eyep.) and a "head unit" without mount/base of some other brand with 1x/3x turret and 10x eyep. and find myself mixing the 20x eyepieces with the 3x head (which are not really interchangeable!) in some very much less than ideal tinkered setup to get a 60x magnification for very minute details of small critters (hairs/tubercles on legs of 2-3mm woodlice, genitalia of harvestmen etc.) all the time wishing for 80x. Honestly though, that clearly is the point where one should decide to make a slide and step over to a regular microscope, but that breaks the workflow. Also, 60x-80x gives you virtually no
DOF and somewhat defeats the purpose of the 3D-experience that the binoc offers - which is absolutely flaming brilliant and indispensable at lower mags.
Most of the time I'm very happy to just use the 20x/40x setup. Not being able to exchange the eyepieces, makes for a tough choice. I would probably have to advice to either get a 1x/3x with 15x eyepiece (for 15x/45x mags) or the 20x/40x model offered.
There is a catch(!)
, that is not documented well on the website: Is the 20x/40x MX-5T a model with a 2x/4x turret and 10x eyepieced? Or is it a 1x/2x turret with 20x eyepieces?
The catch is this: 20x eyepieces usually give you a much smaller "field" - which is mostly due to the the high cost in manufacturing undistorting true wide field oculars at high mags. Of course, manufactures will advertise anything they sell you as "wide field", but that's just talk. So, if the turret is 1x/2x (with 20x oculars) you get a smaller field than a 2x/4x turret with 10x oculars. As there is no price difference with the 1x/3x turret I'm assuming a 1x/2x turret as a 2x/4x turret would involve extra glass (the 1x is a no-lens straight through
In that case I would probably advice the 1x/3x turret with 15x oculars, giving a slightly better max. mag. (45x as opposed to 40x) with the (most likely?!) slightly wider field of the 15x oculars (as opposed to 20x). The same setup (1x/3x turret) with 20x oculars will give you 20x at the low end, which is okay, but 60x at the high end which is not often really needed (unless you plan to do really tiny stuff) and significantly less comfortable than 40/45x (even less DOF, which is already low at 40x). For general purpose I would go with the 40/45x times max. mag. even if 60x seems appealing.
Incidentally, the MX-6T would still be (just) within the budget indicated, but if you (occasionally) need the through-light I'm sure you can also device a LED-laden platter to fit under the specimen for well under the additional £33 or so.
shop around for second hand. Microscopes don't suffer much wear (just check the optics for scratches) and people tend to get either bored with it or they become professionals and upgrade to high end zoomable solutions with much better optics at every level (which really does make a differnece!). I got my Olympus 20x/40x for 20 Euros from a university surplus - with the help of a friend who works there, but you should be able to get a decent starters kit for around £50 second hand anywhere I think. The other day I could buy something like this zoom trinocular
with 12x-80x zoom for some 250 Euros (maybe less, but I didn't have the money anyway of course), which approaches your budget and is a much better piece of hardware.