I have started manually for my coffee journey and am just about to upgrade to a machine so I will be in the position to have a camping set as well.
This will be a Presso and a Kyocera hand grinder, depending on where you shop all up it should come to around $250 or less if there are discounts for going to a sponsor, see the left hand side list. You can find the Kyocera for as little as $88 with free shipping and the Presso you buy from Presso Australia and there might still be the CS discount applicable.
The Presso will give espresso shots, I use 15-18 grams of coffee and pull a 60ml shot.* The Kyocera grind collector section fits exactly into the Presso portafilter.* Also with the Presso you only need a jug/billy to heat water and then pour the water into the Presso and pull your shot.
There are other options out there but it depends on what type of coffee you want, as you said espresso I gave you the above, and it is what I would use.
Other will say to get an aeropress but I dont feel that it gives an espresso shot, I havent used one yet though, just going off videos of them on youtube and what others have said.