Arsenal manager Arsene Wenger has used Manchester United's signing of Anthony Martial as an example to show that big clubs have to pay over the odds if they want to improve their squads in the current transfer market..
United splashed out £36 million on Tuesday to sign Martial, 19, from Monaco -- making him the most expensive teenager in history -- to take the club's spending for the summer past £100m.
The Gunners, meanwhile, spent just £11m on Petr Cech during the transfer window, with Wenger reiterating in recent months that he would only spend big on a player that he truly believed would bolster his options.
As a result, the Arsenal Supporters' Trust has called on the club to carry out a "full review" of their recruitment policy, but Wenger has defended his summer dealings by suggesting he was not prepared to pay the type of fee that United stumped up.
"Monaco sold Martial to Man United last night for €80 million, I've heard. Martial has scored 11 goals in the French championship -- that sums it up," Wenger told beIN Sports.
"It's not the money that is missing at the moment, it's not the desire of investment that is missing, it's the number of players available who can strengthen the big clubs.
"So am I happy with the investment that I made [this summer]? Yes. Every time. I bought [Alexis] Sanchez, I bought [Mesut] Ozil, I bought Cech. I bought Gabriel last year, I bought [Mathieu] Debuchy.
"But when you have to invest, when you find the players to invest the money in, the problem at the moment is to find the players that guarantee that you are absolutely a better team after.
"That example last night shows you very well -- Martial is a huge talent, he's 19 years old. The investment is absolutely huge as well. That shows you there are not many players in the world who can strengthen these teams."
Wenger went on to speak about financial fair play following a summer that has seen UEFA relax the rules after coming down hard on Manchester City and Paris Saint-Germain last year.
With less restrictions placed on them this summer, City went on to spend around £150m, with Kevin De Bruyne and Raheem Sterling brought in for £54m and £49m respectively.
"I'm not against Manchester City or Paris Saint-Germain being able to buy players, but you would like the financial fair play rules to be known before the transfer period starts," Wenger said. "And the rules have been a bit accommodated during the transfer period.
"I cannot give you an answer as to what the real significance of financial fair play is. It's too complicated to be efficient and too complicated for everybody to understand the rules, which is why I think there is a need to simplify the whole process.
"I don't think clubs like Arsenal are being penalised, but I think well-run clubs should be a normality, that every club should live with the resources it produces. At the end of the day, what is a big club and a small club? A big club should be a club with the biggest fan base and which works best in its decisions."