The NFBC, which happens to include some of the best fantasy BB talent in the country, does not allow any trades... just a FA bid system with $1000 budget for the year. The reasoning behind it is because of collusion. Entry fees are $1,300 this year, so you can understand the fear. It makes for a difficult draft because you need to draft EXACTLY what you need. If you go nuts on SB, then you're screwed because you can't trade that talent away. It makes searching the WW really competitive though which is cool.