"If you're running a serious business $75 or even $99 is a bargain"
This is the error Registry.pro have made in their pricing policy, it's why there are only 6,000 .pros registered 3 1/2 years into the life of the extension.
Affilias understood domain economics so after a series of free, $1, and $2 promotions, there are 5m .infos registered at up to $10 per year.
Alternative extensions succeed via a snowball effect and that snowball won't start rolling unless registration is cheap and accessible to everybody at the outset.
.info, .mobi, and .pro are all inferior products to .com and must be priced at a discount at the outset to get the snowball rolling. Once the snowball starts rolling, you get a landrush, once there are millions of domains in circulation, the better keywords become relatively more valuable and people start trading them and selling them on an aftermarket, when people start paying premium prices the domains start getting developed because they have prestige and credibility attached to them and justify the technology investment and marketing.
As more domains get developed aftermarket prices go up, and the millions of people who bought 2 word, 3 words, or dashed domains decide to pay more than the initial discounted price to renew their alternative extension domain. The registry makes a fortune and starts promoting and marketing the extension to business and end users. Domain values go up, more kudos gets attached to the premium domains, businesses see other businesses starting to use the extension, Internet users start accepting it's use, and then, and only then, do business start developing it in volume. This is the point when you can start arguing that to a business $99 is an acceptable registration cost. Until this point businesses haven't heard of it and wouldn't consider using it even if it was free, and Internet users won't accept it because they can't see anybody else using it.
This is how alternative domain extensions develop in the real world. Registry.pro took the short sighted and deluded approach of thinking 1) You can force selected people to develop domains as you see fit, 2) That you can charge people a tenfold premium price for an inferior product and somehow businesses will start using it.
This strategy has been proved wrong time and time again, total domains registered haven't changed significantly for 2 1/2 years and that's a complete joke when you have a credible sounding extension like .pro. Since $49 .pros didn't kickstart the snowball effect, $75 will have virtually no effect on total registrations.