It is not about the can't afford it part, but that companies sometimes can't spread the expenses for software over the bills because they have to compete with other companies. So spending a lot of money for a software piece need to be calculated in the hour price or it takes away the profit.
Not really, unless you are assuming that the software provides no benefit to your company. That would be the same as saying your company builds houses using only hammers while your competitor is using pneumatic nailers ... and you can't afford to buy nailers because you can't charge enough to cover the expense of the equipment or that your company is using a drafting board and mylar and can't afford to buy a computer and AutoCAD because you can't pass that expense to your customer.
Now those scenarios might be 100% accurate if your company only builds one house a year or only designs one building a year, but even then, I suspect that the overhead in labor costs to your company would more than cover the £2,500 expense in the first year.
You need to ask yourself a series of questions:
1) How much will I use the software?
2) Will I eliminate or reduce the need for outside engineers?
3) How much labor will using the new software save or add to my bottom line each time I use it?
By asking those questions, you can make a real case on why you can't afford to not have it.
... and just an FYI, companies don't usually drop their price because they purchased a shiny new tool that makes them more productive, instead, they price their products and services to compete at a better margin than their competitors and increase their bottom line profit.
