The first three books in the Hot Dog Detective series by Mathiya Adams are available in a combined volume at Amazon. The series is available at other retailers (Kobo, Smashwords, etc.) but the omnibus/collection is available only at Amazon (as of now, anyway).
The first three books, and their regular individual prices, are:
Avid Angler: FREE
Busty Ballbreaker: $3.99
Crying Camper: $3.99
The Vol. 1 through 3 omnibus is $5.99
https://www.amazon.com/Hot-Dog-Detec...sap_bc?ie=UTF8
Given with the modest reduction in price over buying the second and third books individually, I'd recommend getting the first book free and then, if you like it, get the omnibus.
The books are published by Misque Press, which seems to be a legitimate, but very small, publisher. However, I read (and really enjoyed!) Avid Angler.
Description:
Spoiler:
Mark MacFarland, former Denver Police Detective, lost everything—his job, his home, his hope for the future--after the man who killed MacFarland's wife was acquitted of the crime. Now, after three years living homeless and drunk on the streets of Denver, he sells hot dogs from a cart located a block from where he used to work.
He's putting his life back together, until he is asked to solve a murder that pits him against the man who had wronged him years earlier.
In Avid Angler, MacFarland defends a woman wrongly accused of murdering her husband. MacFarland discovers his nemesis, Norris Peterson, may be involved in the murder.
In Busty Ballbreaker, MacFarland suspects that an industrial accident was anything but an accident. Is it just a coincidence that the company he is investigating is one of Norris Petersons?
Finally, in Crying Camper, MacFarland rescues missing and exploited homeless children only to learn that Peterson is involved in the exploitation ring.
In three successive novels, MacFarland's confrontation with Norris Peterson, a man of wealth, influence, and power, takes him closer and closer to losing all he has regained from his time on the streets.
Each mystery can be read as a standalone novel, but are best enjoyed when read in order.