They are made in China. Beeman sells them here in the USA. Beeman owns Marksman
I assume you are asking about BB guns not Air soft guns. There are a few that fall under $50 but they are C02 not spring powered. Marksman makes a line of spring pistols under $50 but they are terrible and not worth the cost. See the link below for C02 air guns.
The Lincoln Jeffries air guns were the forerunners of the RWS airguns. They were manufactured from the late 1800's and into the 20's when they became RWS. Today the grandson makes the Marksman brand airgun pellets
Yes, But first determine if it's worth it. Some inexpensive pellet guns are not worth rebuilding. Marksman makes a line of inexpensive air guns and rifles that are not considered very high in quality and may cost more to rebuild than they are worth. However Beeman (Who Owns Marksman) makes very good air guns and rifles, and would be worth the effort to rebuild one. There are several air gun shops around the country that make a living repairing older air guns. You can do a search on the web for "Air gun repair" and locate one that works on your model. Unless you are very handy with tools I would recommend one of there shops, rather than tackle the job yourself. Crosman offers a link on their homepage to independent shops that repair Crosman, Benjamin and Sheridan air guns. All these brands are owned by Crosman. So yes most air guns can be rebuilt.
Diana makes Original Air RIFLES.
First let me explain the relationship of air gun manufactures. Very often air gun companies make air guns for other companies using the new air gun company name. Several air gun companies manufacture air guns under different brand names. Today Beeman owns Marksman air guns. I believe your Marksman 0035 was made by Norica "Of Spain" for sale through Beeman. Your rifle "Marksman 0035", is rated at about 700 FPS. This same rifle is also known as a "Beeman GS700". I picked one up off craigslist a month ago. With 7.9 grain pellets mine shoots at 550 FPS This is good to know. Air gun companies rate their own air guns as far as FPS. Usually they are somewhat over rated. Super lightweight pellets fly very fast but are not as accurate as a heavy weighted pellet that flies straighter and is not as affected by crosswind.
IIRC, Crossman ------------------------------------------- Beeman owns and makes Marksman repeaters not Crosman.
I would start with Beeman air gun co. They own the Marksman line of air guns (See the link below) or go online and look up "air gun repair" and locate someone near you to repair the rifle. Or see the link #2 below.
go on the computer and scan the words 'marksman air pistol' ...............
Unfortunately this rifle is not worth repairing. In Excellent condition it is worth $18. It has an FPS of 250 FPS. That's slower than a Daisy Red Ryder. I really suggest you purchase a new air rifle. These air guns were not designed to be repaired. Marksman is owned by Beeman. If you want to try I suggest you call Marksman at 800-822-8005
I would search the web for "Air gun Repair" and locate a shop near you that can repair it or see the link below for shops that repair air guns.
The marksman model 740 is rated at 425 fps.
Because this question is in the Category of "Air guns and Air rifles" and not in "Airsoft" or the "Paintball" category, I have to assume that you are asking about BB and pellet guns and not regular firearms. The cheapest air/BB gun that I know of is the Marksman 1010C it's around $20. In fact most of the Marksman products are inexpensive. Then I would have to say the Daisy Red Ryder is next on the list. (Every kid I grew up with had one.) It sells for around $30. Personally I think the Marlin "Cowboy" model is nicer and cost around $40. If you are asking about Airsoft guns ( they shoot the larger plastic pellets.) Then place your question in the "Airsoft" Category.