I think Eftpos rental is just one of those unavoidable costs of doing business. Yes, you could roll the dice and take your chances buying a machine, but as has been pointed out, that carries some pretty big and foreseeable risks. Having being in retail, the cost of not having eftpos available (for even a short period like an hour during peak trading) is significantly more than shelling out a monthly rental. Those people who "just nip out to the cash machine" after rolling their eyes at you, may or may not come back.

Be aware of the contract, short terms and/or monthly rent may be the go if you aren't sure of things. Some companies even have a "starting out" period as not to penalize you (too much) in the event that things don't work out.

As for "avoiding stores without paywave"? Maybe I'm too old fashioned, but I rarely use it even if it is available. I like to punch numbers....