Dear Sir, Miss,
Thank you for opening this job for bidding.
Details, like if product descriptions are identical in both csv lists, or if not how many entries will we have to fit manually, must be clarified to be able to give you an exact offer for the hole project. However here I have the pleasure to offer you 3 (net working) hours on your project. In case less time is needed I'll adjust my bid accordingly. In case (much) more time is required to finish the job I may ask you to add additional milestones.
Looking forward to collaborate with you please accept my friendly greetings.
Panagiotis