I cant see this negatively effecting anyone but the people who have set money-based strats. If it becomes a real issue, im sure valve will make it a server option or somthing along those lines.
It negatively effects everyone because the good guns will always increase in price. There's a reason no one uses the UMP, TMP or P90. They are bad guns. All guns in CS are not equal, they never have been. All this update will do is screw up competitive gaming, making it slower, and make more pubs give 16k money so that everyone can afford guns.
A pub with more guns won't be anymore or less fun than it is now. Why? Because those guns suck. Have you ever tried to kill someone with Mac-10? It's 95% luck and 5% skill. Whereas the AK and M4 are 90% skill and 10% luck.
This update will just slow the game down for the competitive scene. I honestly don't see the AK and M4 ever decreasing in price, until they are absurdly expensive (5-6k). At that point, competitive CSS will be dead. There will be maybe 2 gun rounds in the entire half. The rest of the time it will be save, save, save, save until a real gun can be afforded.
CS has been out for 8 years. It has plenty of time to optimize the buying schedule. If a team were to get an advantage by buying SMGs or bad rifles (FAMAS, galil) over saving, then it would have happened already. However, using those guns vs the other who already is established with real guns (AK/M4, AWP) is pointless. Over the years, it's been shown that saving your money for the real guns is a better decision than buying crap guns every round.