WSR 3.5 is about as quick as GP2 now, however they have just got their new car this year, and it will be developed over this year and next year they hope to be around 1 second faster than a GP2 around most tracks. WSR 3.5 is about a quarter the cost of GP2 due to the fact you can buy parts from any one inside WSR 3.5, or buy from the WSR Central Supply Chain. So in effect if you need a engine you can buy from Zytec or buy from another team, if you need a steering wheel you can buy from XAP or DAMS or Caterham Arden.
GP2s cost is around €4.5m a season, and it is a rip off as you have to buy from the GP2 management at inflated costs, and is a claiming rip off, the cost for a steering wheel for a GP2 car is around €3500 from XAP Electronique however GP2 will charge you €6000. The same steering wheel is used in the GP3 and WSR 3.5 car.
WSR 3.5 is growing in popularity, they are trying to pice together for 2014 a 14 race season where they will do around to 10 F1 tracks a season, with 2 rounds every weekend.
WSR has a better grid this year, it has Bianchi, Bird and Rossi and a few other guys that can be placed directly into F1 right now.
GP2 in 2014 is looking to become cheaper, but there is arguments about GP2 at present as the GP2 guys want MES electronics to become closer to F1 with KERS and DRS, but they want to be able to buy from other GP2 teams as well in order to reduce costs.
The other formula that is getting more of a showing than GP2 now is GP3 as it is as cheap as WSR with the same single supplier as GP2, however its new car next year will be vastly quicker, around 4-5 seconds quicker than the c urgent car and will have a naturally aspirated engine in it not the 2 litre turbo. Rumor has it the old WSR engine is the one that will be used.
The lower formulas need to be sorted as its just a mess, their costs are out of control for GP2 and probably for GP3 soon, WSR is looking like the best option for young guys. I think the FIA will soon sort the mess out as to get more young guys in the sport.