I have experienced this first hand and yes most Brokers and Agents are bias against part time agents anyone who tells you different is a lair. From a business standpoint I think it is very stupid and foolish because most agents start off part time.
So imagine being unemployed and living on unemployment then forking over $1,800 to $2,000 to get your license THEN having to pay out $200 a month for desk fee's MLS access and more. And people wonder why most Real Estate Agents either quit or go Broke.
I have also heard horror stories from other part time agents at these large first being given the run around. Other agents abusing them and even other agents cutting them out of deals and/or taking their clients. My advise is to go with a local mom and pop broker and stay away from the large firms as a part timer. Yea they may not have the education or marketing mussel as the big guys but that what the library and internet is for. Also you may find the commission split to be higher as well ; )