Yeah at low salaries the impact of the skill drops aren't that bad for salary efficiency. Not only because the % of a small salary makes the total drop in dollars not big, the skills aren't worth a lot of salary at low levels either. For example, the difference between 8 and 9 Rebound is not even 1k salary difference for a 10k salary center, while it can be up to 10k for 1 skill level beyond 15.
In short, you don't really have to worry if you buy a cheap veteran (both salary and buying price wise).