You better get more than just Shelby Miller for Soler. First off, I want no part of Miller. I would rather them go after either Cleveland pitcher if I had the choice.
Second, since the Cubs have holes to fill, they will probably have to go after a veteran pitcher via free agency, and a young pitcher via trade, and then pursue a CF'er and lead-off man (preferably the same guy) as money would be an issue. Heyward might be a little bit of a long shot here, and doesn't solve the lead-off position, nor CF'er really, even though I'd love to have him and he would fit well in this line-up as young as he is.
If they were to trade for a young pitcher using Soler for instance, and also sign a veteran to give them depth (frankly the Cubs were lucky last year), then they might be able to use some of the farm to go after a stop gap like Ben Revere who is still just 27.
Sure, he has no power, but his OBP is respectable and he gives the Cubs speed at the top of the order. He is 2nd year Arb eligible which would be perfect for the Cubs, because they could be creative enough to still get that MOR pitcher like Lackey, Shark, or Leake.
This could be very close to the dollar figure that they could spend which would be in the 23=25 million dollar area, and still leave about 5 million to throw at the pen.
The Cubs were fairly lucky not to have pitcher go down other than Hammel, and they need to be prepared for that and be at least 6 deep.