We reckon A7 will upgrade memory bandwidth spec to LPDDR3 from LPDDR2 adapted by A6, in an effort to improve system performance. Since Apple is in charge of both hardware and OS design, it is capable of minimalizing memory capacity at an optimized state. Therefore, A7’s RAM will likely be unchanged at 1GB.BTW, I can't see the price and information from t3.com said that "the iPhone 5c will retail for between £230 and £320 SIM free."
iPhone 5S & iPhone 5 (Low Cost) Specification
New iPhone 5S use new A7/28mm chip with 1GB RAM, 8MP camera with F/2.0 aperture and 1.2MP font camera while iPhone 5 (Low Cost) use A6/32mm chip