if you want to play some games while saving up your cash.
Use the free to use army lists on EasyArmy .com.
This allows you to get a feel for how German forces are constructed and how they play.
Reaver 83, is spot on about the nerblewerfer battry and armoured cars for recon.

(Do not leave home without them!)
If you are after getting some Sdkfz 251 half tracks for your infantry .
May I suggest getting 2 boxes of 5 Plastic Soldier Company Sdkfz 251 halftracks.
(2 half tracks for the Company
HQ , and 4 half tracks each for the 2 platoons.)
If you get a box of 5
PSC Stug III that allows 2 platoons of 4 Stug III supporting armour,(Combined with your OF ones .Platoons of 4 are better than platoons of 3 or 5.)
Also
PSC also sell Zevda plastic Sdkfz 222 armoured cars quite cheap too, (as a recon option.)
(In my experiance the
PSC vehicles are high quality and about half the price of
BF ones.)