A vector is a graphic that has been made in a program like Illustrator. Logos are frequently done this way. It ensures that quality is kept whatever size it is used.
Prices for design are normally worked out for the complexity of each project, which is why you don't often see them listed. I have set some of my prices to make it easier for my customers. These may change when we get into the project and I find out how much work is involved, but I will always give quotes in advance of starting any work.
I require £20 or full amount if less as a non-refundable deposit to start working. If I am working for you on a large project I will send interim bills at each stage. I will send an invoice and you can pay direct with online banking, PayPal or send a cheque. Details you need will be on the invoice.