Using 2" and 1.25" barlows together

[Dipper]

I have a SkyWatcher Quattro telescope with 2" focuser (and also a 1.25" adaptor) and am looking for a barlow. With a short tube (800 f/4) I feel like I need more than a 2x barlow for imaging planets, but the problem is that 2" barlows aren't cheap.

I wonder, is it possible to use a 2" barlow AND a 1.25" barlow for photographic uses (say, two inch 2x barlow plus one and a quarter inch 2x barlow)? On the end of the second barlow I would screw a 1.25" -> T2 adaptor and then the DSLR. Technically it all makes sense but would there be any vignetting or some other optical issues? Here's an illustration of what I mean.

[Dipper]

Oh come on, there must be people using 1.25" barlow with a T2 to attach DSLR to comment on that!

[Geys1987]

I don't think that vignetting will be a big problem since planets are relatively small targets.

I'm a bit more concerned about image degradation when stacking multiple barlows. You're introducing a couple of items (more optical surfaces, more possibilities for misalignment, ...).

If planets are your main interest, why not invest in something like a 5x powermate?

[faulksy]

or a mak or sct