There are also a number of operators who bill you for R22 datcon (ie. engine running time - the datcon is oil pressure activated), but subtract 0.1 from that for the tech log.
The R44 is somewhat easier to fly than the R22, since things happen slower and it's less twitchy. That said, I suspect you'd still have to try quite hard to make doing a PPL in a R44 cost less than in a R22.
As always, the question you should be asking yourself is what you're planning to do once you have a license. If you're going to go buy your own R44, then you might be better off doing the training in the same machine, even though it costs more; if you're wanting to go commercial, say north sea or police, you might as well do the training in whatever's cheapest (unless you can afford to do it in a squirrel or gazelle or something), which generally translates to the R22.