What do I do if I charge clients different amounts for service every project? There is no hourly rate, only a project rate. It's a one-time price each time.
I don't want to put in titles like "Project for IBM - Create documentation" $2,700, and "Project for Google - add software application xyz" $14,200. Because then everyone can see what I am charging those companies, or companies can see what I am charging other companies. What I would like to do is just have a purchase page where they type in the price that I give them over the phone. I've had this in the past with credit card companies. Does shopify have it?
Also, I don't see if there's a maximum amount I'm allowed to have clients pay over Shopify.
I'm not aware of any way to add a variable price on an item for people to enter manually.
However you can have variable quantity, which is how I've handled this in the past. If your pricing is always in even 100's make it $100, but it could be $10 or $1 if necessary. $1 is probably the simplest realistically. Then they just type the price in the quantity.
I haven't looked into this at all as quantity is fine for what I use it for, but I'm pretty sure if you wanted to you could even make a custom template for these items without too much trouble and change the "Quantity" field so it's labelled "Enter Quoted Price" or similar. You send them a link, they punch it in and hit purchase. When they get to checkout it would still say they're buying 12,000x units of "software development" etc. but I don't think that would be a big issue.
Alternatively I believe there was a "tip jar" at checkout added recently. I haven't enabled or messed around with it at all but this might permit people to enter an amount manually to add to their transaction.