Add additional characters to already populated cell based on data entered in another cell

I am attempting to figure out a formula to add additional text characters to an already populated cell.
Let me explain,
I am looking to generate a "Reference number" or "code number" based on what i have entered into another field,
all of my "reference numbers" begin with the same beginning characters (REF#1000-)
The final 3 or 4 numbers of the reference are based on the price i enter into another field,
if my price is $5.75 my "reference number" must end with 575, so my reference number in this instance would be REF#1000-575
Is there a way i can input a formula so that the 575 is added to the REF#1000- once i input the price into the appropriate cell?
I dont want to have to manually type out each reference number as there are multiple prices i will be inputting into the PRICE field.

I hope this is clear, this is my first post on excelforum.com

Thank you for your assistance.

Thank you, this is exactly what I needed.