I bought one of these kids-drumkit with the intent of building a little cafe-drumkit.
16" bas-drum, 10" snare, 8" tom and a totally trashed cymbal for 13,5€ :-)

I was lucky to have most of the things I needed, but if I had to buy all the parts separately, I might as well have bought a used cafe-drumkit, the bass-drum-riser alone cost 20€.

I also added a 12" tom to use as floor-tom (attached to the cymbal stand), a grown-up bd-pedal, hi-hat/cymbal stands, changed the plastic heads with some old heads I had and lastly added the hi-hat and cymbal.

I did get a nice little kit out of it thou, a kit that's small enough to be transported on public transport, and the sound is not bad, might even ad the little "popcorn" snare to my regular setup.

I'll mic it up one of these days and post a small recording.