Leener,
I started out using propay (for 2 years) before going on to a regular CC processor. More and more people started using credit cards, and I got sick of propay transactions taking 3 to 5 minutes to complete.
Propay is great because there is a once a year charge, and then nothing unless you process cards. People who use credit cards end up spending more, so I think it is totally worth it.
You need to build a little slack into your rates, its like wearing elastic pants. Sometimes you need a little extra space when you eat a big meal, and sometimes you need a little extra padding built into your rates to account for credit card processing fees. If your money within your practice is so tight that you cannot afford to risk the 5% that spaboom requires and/or the $2 to $3 extra a cc processor will take, then you need to raise your rates for ALL your clients OR get more clients.
Keep in mind, not all your clients are going to jump on the credit card band wagon. SO, you wont be paying a % for all of your clients.
Besides, in a service type of business, there is A LOT more slack built in than a retail business. Once you reach a certain client load, the amount a massage actually costs goes down quite a bit. For example, if your costs to operate your own massage room equal $500 per month, and you only have one client a month, then that one massage's actual expences are $500. But, if you have 20 clients a week, the actual cost per client goes down greatly, even when you take into account the extra oils, laundry, paperwork, etc... incured (say about $200 extra). At 20 clients a week, we are talking about an actual cost per massage to be between $8 and $10. This of course, doesnt include paying yourself. Even if you are marketing yourself heavily to get all those clients and spend $500 over and above the first mentioned $500 for a total expence of $1000 a month, that is only $12.50 per massage.
Accepting credit cards helps my business stand out in my area as well.
I rambled I know. Hope it made sense.