Hi.
As a matter of a fact I bought a cheap POS Millenium e-drum set just yesterday.
In all fairness I have to admit that my first set in the late 80's was a Pearl World double BD set with 10 cymbals though

. This is only my second set as I quit drumming alltogether when I sold that dinosaur kit.
As You probably don't have too much experience with drumming, I'd strongly suggest that You look for e-kits. Established drummers find them quite hard at first, some won't (don't want to ?) ever learn to play with them. The feel, touch and about everything about them is different than with acoustic drums. No problem if You're just starting out.
However the benefits are manyfold. Ease of transportation, ease of maintenance, relatively silent, so practising isn't a problem. The last, but not least, the gig volume is "easily" controlled. "Easily", because e-drums have a huge drawback in one regard. E-drums need a hefty amplification to match a hard hitting acoustic kit drummer. When I did pro-sound back in the day, the e-drums were a rarity, but the few acts that had those were quite problematic. The low/low-mid amps starved QUICKLY, and the synth BD was really hard on the cabs. Also the on stage monitors were at their limit. E-drums required totally different EQ ing and compression than an acoustic ones. The sound was fantastic at the end though.
When I was calculating between the e-drums and acoustic kits, I found out that e-drums cost about twice when gig ready.
As for where to buy: CL, e-bay, fellow musicians etc. It seems to me that almost everyone has an old POS kit in their basement (Just like Token had the bass in his...

)
Regards
Sam