Yes, Fein invented the multi tool and held patents freezing out competitors til about 2010.And it looks like they, in conjunction with Bosch, are doing it again. Since March this year all new Fein and Bosch multitools available in the UK have been supplied with the StarLock system tool mounting. To date StarLock tooling (a patented design) is only available from those two manufacturers and the new tools won't use the older tooling, so if you buy a new tool you are locked into the more expensive blades fom Fein and Bosch. Maybe not much of a problem if you are using a few blades a year but on the current project we've got 4 or 5 trades using a dozen or more multitools so it very soon adds up. I'm currently using 4 to 6 blades a month at the moment as are two other carpenters. We've already sent back one new Fein Multimaster and requested an older/different model from the dealer (ended up with an new old-stock Bosch GOP). I don't see us being alone doing that.
The multimaster blades may be or seem expensive when compared to reciprocating or jigsaw blades, but the current cost is far less than it used to be.
My first Multimaster was a MSX636-2 model, which at the time had a list price of $250, and a street price between $150 and $200. I purchased it before the multimasters were being sold thru major stores like Home Depot. At the time you had to purchase Fein blades, and the basic round "regular" steel blades were around $25 each. I'm not sure whether the Fein "high speed steel, hss" blades were even available yet, but I recall a price of about $50 each for the hss when they were. I remmember the offset hss steel blades were even more expensive, and according to an old price list I have had a list price of atound $80, and I don't recall a discount on those of more than 25% ffom retailers. The Fein E-cut blades when they were introduced had a price around $40 or up.
The current cost of the Fein oscillating blades according to The Toolnut website, is mostly $16 or less per blade, with many around $12. Bosch oscillating blades are even more affordable. The Bosch blades seem to be about $10 each or less, with the carbide toothed ones being $16, or less each if you buy a multi pack.
Prices in the UK seem to be about the same.
Meanwhile, good jigsaw and reciprocating saw blades have been getting more expensive, with the possible exception of the newer carbide tipped ones which in some cases have gotten more affordable.