getagrip:
Actually, if you pay in full, WA comes out to $29.99 a month, but you get quite a bit for that, including a bunch of tools and website builder in Site Rubix, PLUS things like Niche Q. You can also host up to 3 domains with Wealthy Affiliate Web Hosting - with SBI, you have to pay a minimum of $100 additional for each new domain you add on - and that is only if you can get the special offer - otherwise it is an additional $300.
I think it would be beneficial for SBI to offer monthly billing - even if they charged $30 a month for the option to go month to month, because that $300 is cost prohibitive for a lot of people. I'm glad its a good quality program though - but let's face it, even though $40 a month is more expensive than paying $300 up front, its still a lot more affordable for most people, and WA will pay for itself with just two referrals.
Having said all of that, both WA and SBI are great programs. You can't go wrong with either one.