You might want to check out this thread:
https://bitcointalksearch.org/topic/m.2197347
Only the last three rows of the table are currently useful... but maybe it will improve as Avalon starts shipping chips, etc.
Right now I believe the earliest option is BlackArrow with arrival around July?
Topic: [WTB] Afordable FPGA/ASIC for testing... (Read 742 times)
At the moment don't care for speed but feel its pointless paying 10x $/MH for ASIC/FPGA compared to GPU. For instance 7870XT costs $250 and can do 450-500MH/s. If I'm not paying for electricity what is the point paying $1000-3000 for the same thing? I'll look into the two you mentioned.
If you don't care about hash speed, Black arrow (fpga) and bit fountain (USB asic) each have something for around ~375 USD though they both are pretty low hash rate (300Mhs?).
Is there anything out there that is at least as affordable $/MH and under $500 as GPU for a beginner to test off of 
Ideally would like to test off a raspberry pi.
Ideally would like to test off a raspberry pi. Jump to: