Leaving aside the hardware and connection considerations, who is entitled to 'taste' domains? Is this just for registrars? If so, what do you need to be a registrar? I saw a thread somewhere mentioning showing $70,000 in the bank and some other costs.
It's mainly registrars but some do pass on this 'benefit' to their customers. I believe you can taste via a Moniker account.
anyone can taste, some registers charge though like Godaddy but some don't charge anything as long as it is returned within 5 days. If you are a register then you can taste all you like in bulk
Only registrars are granted the 5 day grace period from ICANN/VeriSign so you have to find one to do it for you. People have mentioned a few here that will do it..usually for 5-25 cents a piece. To taste from the registry (Verisign for .com and .net) you have to pay for it at the time of registration and then get a refund. So you have to have the full reg fee for all the names you want to taste and drop them in under 5 days. So if you registrar charges $8 per yu would need $800 to taste 100. To get any results you would at least 1000 domains. Takes Money to make money!
Dynadot does it for free too (you do need to pay the fee up-front, but get another full domain credit if you delete a domain within five days). If you have a smaller budget, you can start with 100 or even 50 domains per day and only keep those domains that earn at least 10 times the reg fee, i.e. more than $0.19 per day. After a week or so of proven traffic and revenue, you can sell these domains for 12 to 18 months' revenue, and reinvest the profits to increase the number of domains you are testing each day.