Spreadsheet for Fees, Shipping, Profit, ETC for selling on EBAY

Hi -

I am trying to create a spreadsheet to found out the fees that would be charged if I was to sell some items on EBAY.

I have completed the attached.

I am having problems in the > 50.00 cell (($50.01–$1,000.00) and the formula to use.
If I sell something more then $50.01, the Final Value Fee (cell Q) is $5.00 of the first $50.00, then 8% for the remaining amount. Example $89.00 total: $5.00 plus $39.00 x .08

See formula currently using: See Cell T2
=ROUND(L2*2.9%+0.3+O2+S2*M2+K2+R2+IF(L2<=50,P2),2)


Also, the fee's stated above are based on the Selling Price and Shipping fees
so I need to base my Final Value Fee to included the Shipping Fee Cell (K2)

See formula currently using: See Cell T2
=ROUND(L2*2.9%+0.3+O2+S2*M2+K2+R2+IF(L2<=50,P2),2)

S2*M2 is the formula used to add the .15 per photo fee. I may have inputted this in correctly into the formula.

Thanks for your help.