Welcome to TRS
Yes, with the backorders of new trucks, used truck prices are high now
The 2.5l was the last in the SOHC Lima engines, built in Ford's Lima, Ohio engine plant
It started out in a 1974 Pinto, as 2.3l SOHC so has a nick name, The Pinto Engine
Very very reliable engine
But does have a timing BELT which needs to be changed every 80-100k miles or so
Its a non-interference engine so a broken belt won't hurt pistons or valves but engine will of course stop running, lol
In 1989 the 2.3l Lima was changed to distributorless and got dual spark plugs for more power, both spark plugs fire at the same time
In 1998 the 2.3l Lima was stroked, same pistons, head and block, but different crank and longer connecting rods, and this version was only used from 1998 to 2001, as you said
A 27 year run, which never happens unless an engine is reliable, lol
Rangers got PATS(passive anti-theft system) in 1999, but only the V6 models, needs transponder key to start the engine
The 4cyl didn't have PATS until the 2.3l DOHC Duratec was used
So the 2.5l won't have PATS regardless of the year
Mid-year 2001 Rangers got the new 2.3l DOHC Duratec engine, so mid-2001 was the last of the Limas
Its not a power house but can get out of its own way, and the MPG is OK for 1990's technology
Paired with the M5OD-R1(M5R1) manual transmission, this combo is usually trouble free
M5R1 was used from 1988 thru 2011 in Rangers so also a reliable part/transmission
1998 thru 2003 Ranger were analog, and before that as well, lol
2004 thru 2011 Rangers had digital dash and CAN Bus data network
2001 thru 2003 Ranger 2.3l DOHC had heated thermostats and IMRC which had issues, these were both dropped in 2004 Rangers
The 1994 thru 2011 Mazda B-series were Ford Rangers, B2300 has 2.3l engine, B2500 has 2.5l engine, B3000 has 3.0l V6, B4000 has the 4.0l V6
These are often sold cheaper and its the same chassis and drive train with different body panels
So same reliability of a Ford Ranger but costs less, but they didn't sell as well as Rangers so fewer around
Used Ranger buyers guide seen here:
https://www.therangerstation.com/ford-rangers-buyers-guide/
And you can look at Brochures here:
https://www.therangerstation.com/articles/ford-ranger-brochures/
To see what Trim packages and Options were for the year you are considering