I bloody loved having my lashes done - when done properly your natural lashes aren't damaged, imo they look better than strip lashes and they last much longer. I only stopped having mine done professionally to cut down on my outgoings and now do my own but they look nowhere near as good as the ones done by a proper lash tech!
Is it worth the money?
As long as you have enough disposable income to ensure that you aren't sacrificing something else, cutting yourself short or anything like that (which I'm sure you've already considered) then yes, absolutely. They are one of the first "treats" I will resume for myself once my financial situation improves. I found that with lash extensions, I didn't need any other makeup other than a bit of concealer under my eyes to brighten them up. Literally nothing else. BLISS!
Do they need a lot of upkeep?
Not really. Just get a lash cleaning foam and a little brush, and very gently clean them every couple of days especially along your lash line. Also brush them after you get out of the shower so they dry nicely. This stops them getting clumped/twisted.
The difference between classic and hybrid?
I'm not a professional but I believe the hybrid are fluffier/thicker? It's what I always went for as the classic style was a bit too minimal for me but still looked absolutely beautiful! Just not the look I was going for.
Do you still wear mascara with them?!
Nope - my technician specifically told me not to wear mascara with them. This is because you don't need to but also because it sticks to the extensions, making them look/appear grubby, bacteria can stick to any mascara you don't manage to clean off and they can shed quicker if you put mascara on.
Every lash technician is different so if you go ahead with getting lashes, one tech's lashes might last you 2 weeks while another tech's might last you 4. Look at reviews etc, photos of previous work etc. I had to go for infills every 3 weeks to maintain my lashes but could have gone every 4 if needed.
Also the first time I had lash extensions, my tech warned me they might fall out quicker than expected (they did) but she said this is quite often the case and after your 2nd or 3rd time, your lashes will begin to "hold" extensions better.
Good luck OP :)