Not compared to what a working original Space Invaders machine would cost! I went to the G.A.M.E. exhibition in London last year which covered computer games from Pong forwards and was brilliant. It was meant to be touring the world, so look out for it.
I'm not sure this is going to be a hit. Obtain a copy of the original Space Invaders ROM and stick it in MAME, and have a quick go of it. You know, with your fingers crossed, so it's not illegal. It's hard! And repetitive! And it'll probably be a dollar a shot! It should be 20 cents a throw here, or a quarter in the US, and not a fortune. Retro gaming needs retro prices!
Plus most of the people who play them at trendy bars etc. are pretty tanked. At $2 a game for drunks to play space invaders, you'll be catching up to Bill Gates any day. Leaves the old 'hotdogs outside of pubs' racket for dead.
One word: Expensive.