Pulis' team are 13th in the table, six points above the relegation zone, and he said he must sell players in the window before he can buy.
"If we move people out, I'm hoping we get a little bit of money to reinvest because we need to," he told the BBC ahead of Saturday's league game at home to Stoke City. "But we have to move people out before we can move people in.
"We're not in a position where we can spend millions blowing everyone out of the water, where we can go out and offer people 100,000 pounds ($147,430) a week (in wages).
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"We're sat on the top table but we feed off the crumbs ... you have to wait for those crumbs to drop off the table and hopefully you're in the right place at the right time to pick them up.
"That doesn't happen at the start of a meal. That usually happens at the end of the meal."
Pulis predicted plenty of transfer activity among the leading teams.
"I have a feeling that maybe the top four or five clubs will spend during this window to make themselves stronger," he said.
Arsenal and Leicester City are leading the way with 39 points from 19 matches followed by Manchester City on 36, Tottenham Hotspur with 35 and Crystal Palace on 31.
(Writing by Tony Jimenez; Editing by Mark Lamport-Stokes)
