Yes, there are still plenty of invasion books floating around. We tried to get them unblessed a few years back, but to no avail.
The books come in two types: one has three properties and goes up to a maximum of MR-3, SDI-30, LRC-10. The more valuable version has four properties to a maximum of DCI-10, SDI-30, FCR-2, LMC-5. Someone sold an average one of these (DCI-5, SDI-21, FCR-1, LMC-4) at the auction and it fetched 5.5 million. I imagine one with max stats would fetch tens of millions.