It's not huge, by rich-people standards (which is a legitimate concern, as it does lead to very rich people being more able to take politician jobs than regular people), but, what, you thought they relied on graft to buy their dinners??
I agree, and trading stocks is not keeping poor people from becoming elected officials either
Even as it stands, just relying on their Congressional salary, it can be difficult for Congresspeople to maintain a residence in their district and one in DC—which is a fairly expensive real estate market—which is effectively a requirement of their position. Within some fairly clear limits, increasing the salary paid to those in Congress would have a tendency to decrease their reliance on lobbying money, rather than increase their appetite for it.
Rather than paying our politicians more to hopefully prevent them from being corrupt I'd suggest putting them in prison anytime we catch even a slight whiff of impropriety.
They will if this ban is instituted