Struggling with IF function

Hi there. I am new to the forum and also new to excel. If anybody could please help me with a formula that would solve my problem, I would really appreciate it. I have tried certain range of the IF, AND, as well as OR functions but was still not able to get the results I am looking for. For the sake of argument:

if A1 is between 1 and 25, the value in B1 should be 2500
if A1 is between 26 and 50, the value in B1 should be 5000
if A1 is between 51 and 75, the value in B1 should be 7500
if A1 is between 76 and 100, the value in B1 should be 10000
if A1 is between 101 and 125, the value in B1 should be 12500
if A1 is between 126 and 150, the value in B1 should be 15000
if A1 is between 151 and 175, the value in B1 should be 17500
Etc

What formula can I use?

Thank you for your responses. Please bear with me as I have very little experience. I have copied the LOOKUP formula provided by AliGW, but it gives me #N/A answer. The number is A1 currently is 3, so I would be hoping for a 2500 response since the value is between 1 and 25.

Make sure that A1 is formatted to either General or Number.

Thank you for all your help thus far. I have checked, and A1 is formatted general. A1 is however the sum of B1 and C1 (=sum(B1+C1), not sure if that would make a difference. I still get the same #N/A response under the suggested LOOKUP formula. I have tried the FLOOR formula as well, but get a #VALUE! response in that case.

My apologies to AliGW and and vlady as both your formulas work perfectly. I needed A2 instead of A1 in my formula - blond moment as I have a header. Thank you again.