You only get so many shots in life. Shoot your shot. If it's a no, accept it graciously and move on.

"We talked for a few hours on the phone..." Dude, ask her out.

Often times we get stuck in the what-if and it comes with a lot of anxiety and worry about trying to find the "right" thing to do or say. But what helps me is asking myself the question, "wouldn't you rather know?"

I've been denied by many beautiful women and I've been accepted by others I never thought I'd have a chance with. The only ones that I regret are the ones I never had the courage to ask. Life's short my friend, don't burden yourself with worry and wonder. Give it a try, just ask her honestly and be ok with whatever the answer is.

If she just wants to help with the house? Great, you have a better chance of becoming friends now that you're not worried about what she thinks of you. If she's unsure or says yes, then just let things develop as they will. Worst case scenario, she doesn't talk to you anymore...sad yes, but at least you can look for someone who wants you back!

I don't know how much time that job takes, but if you ask her out after she completed it, she can just say no without having to see you again and without feeling like she has to say yes because of the ongoing job

I’m coming at you with the confidence of a complete internet stranger that is not in your situation, not in your shoes, and not in the same mindset as you.
I say that because I think I could do this right now at this time in my life, with how I currently feel, but I know absolutely, that I would not have had this level of confidence at certain points in my life - heck, even at many points in my life.

But here’s my completely ungrounded in your reality suggestion:
Figure out if you are going to go with another quote. If you are, then commit to yourself not to change your mind on that unless she offers a requote, but well… I’ll explain further down.
Call her up, and give her the rundown. For me, that would look like this - I’d make sure she had at least a few minutes to talk, and I’d say something like “I have a couple issues I’m currently trying to work through regarding this project, and I need your help.” I’d say that her quote came in a bit higher than others, and maybe even make a point to say that you know her work is worth it, but you don’t have the budget for it. If she offers to change her quote, I’d stop her, and say something like “I’m not opposed to that, but before we talk about that, I want to talk about my other issue.”
Next, I’d steer the conversation to the next thing you wanted to talk about. I’d tell her that my other problem is that I really have enjoyed working with her and I’d like to ask her on a date if she was interested, but I’m worried that asking her out might be problematic - I wouldn’t want her to feel beholden since you have a working relationship. I would be very, very clear - that no matter her response, you’ve already left her glowing online reviews, will continue to recommend her to your friends, and if she still wants to offer a revised quote, you won’t show it favoritism if she does go on a date with you.

It’s important that you impress on her that she doesn’t have to go on a date with you to get work. (You might want to say that.) You don’t want a power imbalance there. Heck, I’d even tell her it’s totally fine if she wants to end your personal/professional relationship as a result.

Good luck! I hope you find happiness.