Inside skills cost more actually if I'm not wrong...
Inside skills definitely cost less than outside skills. Purely because it is faster to train inside skills.
Exhibit A: Daniel Peixet
(3013244) of team Ginakia. A 95K center which he bought for only $3.1M in July. The highest salary player in MBBA for season 9 and 10.
Exhibit B: Mohd Ariffin bin Azizan
(6918930) of team Ginakia. A 26K PG which he sold for $2.8M in September
The difference in salary is 70K but the price difference is only a meager $300K.
There are plenty of examples if you just check on the transfer history of other teams. I am referring to team Ginakia a lot since they are currently in the forefront in terms of total player salary.
For outside players you might not feel it since you never sold inside players. But for me and Damientor we know that inside players sell a lot cheaper than outside players for the same salary. Which is actually understandable considering the fact that inside players takes half the time of outside players to get a pop in skill.