Having just gone through this, and also experienced home buying before this market madness, here is how I look at it:
Normal inspection routine
In normal times, you see a home you like and place an offer which includes contingencies for inspections. If your offer is accepted, the inspection contingency period kicks in, giving you usually a week or two to hire one or more inspectors to look the place over. A general inspection takes 2-4 hours and a report usually comes within a day or two after that. Maybe your contingency says "Unless we find a repair costing more than $3,000, we commit to making the purchase we offered." Or maybe it doesn't include that, in which case an inspection is a buyer's chance to negotiate the price or walk away for anything they find during the inspection.
Today's market waiving inspection contingencies
In the extreme seller's market we're in now, many homes are being bought without an inspection contingency. One way that happens is buyers taking a careful look during the showing and/or taking a risk in buying the home with parts of it sight-unseen.
Getting a pre-offer inspection
One way to make a purchase offer without any inspection contingency, but without the risk of no inspection at all, is to get a pre-offer inspection. That's what I did, after learning how many other people were doing it nowadays. I had to call around because many inspectors do not want to do a casual walk-through during a showing and make any claims about what they see. In my case, the inspector (and me!) wanted a normal, full general inspection, taking 2-4 hours and producing a report I can refer to later on. Because the market is so hot, this required me lining up the inspector in advance, seeing the house and confirming I want to spend around $500 on an inspector even if my offer is not accepted, and asking the seller for permission to do the pre-offer inspection (providing access, a sufficient chunk of time, and allowing a report to be written). I think the seller allowed this because they knew we were serious about making a good offer, so if letting us spend our own cash and 3 hours at their house would enable the seller to get a good offer without an inspection contingency, that sounds good to them. On my end, I was ready to eat the $500 cost, a few times if needed. I'd only do this for a house I was ready to make my strongest offer on.
This worked well for me: saw the house on the 2nd day it was on the market, inspected it on the 3rd day, and the inspector was good enough to get me the report within just hours of the inspection. That enabled me to put an offer in without an inspection contingency on that night, and that makes for a much stronger offer. An inspection is not a tell-all though, some questions can remain about specialized systems and there might not be time to get a, say, structural engineer to look at something. In my case, during the inspection, I was sending photos and asking expert advice from folks willing to provide it from afar, and I had my own and my realtor's experience to give me more confidence about the purchase price and likely future costs.
wouldn't I have lost money and time
I don't understand this line. Certainly you would lose time, but I don't see how you've lost money. Indeed, if you do it the other way around, you're more likely to lose money. If you commission (and pay for) the report,and then seller doesn't like your offer (or they've had a better offer in the meantime, then you're money is entirely wasted, even if the report comes back clean!