OTC stocks or those soon to be delisted are not permitted for many funds (and for many brokers managing other people's money). In addition, most brokers begin charging a per-share fee commission structure for over a certain number of shares. Usually $0.01. For instance, my broker charges a flat $12 commission plus $3 for limit orders (which are necessary for buying these deals unless you want a market maker to kill you). However, for orders over 2,500 shares, you've got to pay $0.01/shr instead of the flat $12.
Of course, to make it worth your while on these spread trades, you've got to get enough in dollar terms and thus thousands of shares.
Let's say you want 7,500 shares of AGNT. I'd pay commissions of $78 or split into three trades and pay $45. Either way, trading these isn't as cheap as normal shares.
Dont know what idiot broker you use...but i buy large amounts of stocks like this, sometimes bid for as much as 200,000 shares at once and that order costs me $11.00 commission..whether its 1,000 shares or 200,000 shares or whatever...