The base annual salary for Senators and Representatives in 2010 is $174,000. In addition there are retirement and health benefits, expense allowances, franking privilege, personal staff allowance and other perquisites.
The 2010 median household income in the United States is $49,777.
Since a proportionally representative Citizen Legislature would contain half above and half below the median income, the representatives might want to peg the salary to a certain percentage of that median.
[In The Common Lot: Next Step for Democracy it is proposed that the salary be exactly the national median. Upon further reflection however, considering the considerable dislocation required and effort demanded, perhaps the national median plus 50% would be appropriate and adequate.]
In any case, this would be a matter for considered debate, as it always is and will remain.