Probably too high for a Senior. They mostly go for no higher than 0.4 but they seem to be struggling to get that with a few sales for much cheaper at 0.25+.
A Senior account with 240ish activity is long to make but there are not a lot of demand because big signature participants already have many of them and can build new ones while there are a good amount in offer if needed.
0.5 is higher than what he should expect for it now. 0.3 is possible.