I would really like a limit (upper limit) for payment systems to deactivate it's use.
 
The main reason is I don't trust PayPal for large ticket items. I'd like to say OK, you can use PayPal but only if it's an order under $200 for example.

PayPal has always treated me well... I have used them for years. For many years they were my sole payment method.

I use PayPal and take orders up to stg£2,000 (about $3,000) with no problems.
 
I have used PayPal in the UK for three years and am very pleased with it.
 
We do, nevertheless, require customers to be checked by us before we accept a large payment - we do this by refunding new large payments and asking for a bank credit for that first order.
 
Chris