My view is that a morph fills a role in transhumanity roughly equivalent to that of a modern day car. Your average person my switch to a new morph once every 5 years or so, but within that average you have a lot of variability. Some people might swap as often as every six months or so, so people might hold a morph for over 15 years (especially if the morph is a 'classic'). Some people run their morph into the ground and some people take exceptional care of their morphs. Most people only own a single morph though enough people own more than one that it is hardly an eyebrow raising surprise to find someone owns multiple ones. I find that thinking of morphs in these terms really helps with a lot of things (incidentally, I also tend to think of ego casting in terms of modern day air travel). It lets me understand that in some locations there are probably a much higher number of people without any morphs (i.e. infomorphs). The structure of where they live means that they can get by fine without owning a morph the vast majority of the time. On those occasions where they really do need a morph (such as going on a vacation) they just rent one. There may even be setups where unattended morphs kind of sit around and anyone can rent the morph for a few hours (similar to how Car2Go works). There are certainly the companies that rent morphs for average use for people who are ego casting or who are unable to use their current morph for some reason. There are also companies that deal with specialized morphs such as morphs for construction projects or luxury morphs. With all that said my answer of how often a player has to resleeve is 'it depends'. Players probably go through morphs a lot more often than your average transhuman (PCs being exceptional individuals) but that will still usually translate to not terribly often (unless they are upgrading) in most cases. On the other hand campaigns in which characters are trouble shooters and ego cast throughout the solar system will often have a high rate of resleeving and likewise a campaign where the characters are the transhuman equivalent of James Bond might have them resleeve every mission (Let's go through a few of the more interesting features of your new morph, 007).

Usually around once every 1 or 2 sessions. Mostly from farcasting around the solar system. I had one session where all the players switched morphs 3 times in the same session.