A ninth home victory of the season against Reading on Sunday would secure a top-half finish - a handsome return for last year's Championship play-off winners - but Allardyce knows further progress for his side will be a different matter.
"For the small improvement, it is a considerable amount of millions which is needed today, that is the difficulty we all face," Allardyce told Talksport.
"You buy a £10m player or a £12m player today and everybody expects the team to improve by 15 or 20 per cent, but often it is only by one or two per cent.
"The size of the fees for players and wages just don't relate to how much they improve the team.
"That brings more and more pressure on you as a manager in trying to improve the side.... but the money needed today is astronomical.
"We have got some funds available, but the financial restrictions kick in this year and those funds will be restricted.
"We have to be careful where, and how, we spend our money to try and improve the side, which is something we must do.
"It is worrying for everybody and we will have to see how it works out. It makes life that little bit more difficult.
"But we will have to learn to deal with it and, hopefully as a team, we can get better despite those restrictions."