Agree with Tangerino about how the AI values top picks, although I haven't tried anything like he did with the offer. Doesn't surprise me though.
There's a lot to consider when making a trade like this though.
Ask yourself some questions:
Is the #1 pick going to be a generational talent?
Is he going to turn my team into a contender right away?
Where am I with my rebuild? (question 2 applies here also - if I get #1, is he the missing piece?)
How much am I willing to give up? If you are going to give up your next 3 firsts, then you should be close to ready. If you think your team will still struggle for a couple more years, then you're trading away what are likely to be high picks in the first round. So you have to consider that too.
So much to consider - the life of a GM