What is a 1850 Helvetia coin?

Helvetia is the Latin name that the Romans gave to Switzerland area over 2000 years ago. The Swiss achieved an independent confederation of its cantons in 1291, and each canton was issuing its own coins until the unified coinage began in 1850. Main currency was a Swiss Franc. There were 100 rappen, or centimes, in one Swiss Franc.
There were 6.16 million of low grade silver 20 rappen coins minted in Strasbourg (BB) in year 1850 and its today's value may range from about $10 with heavy wear to around $100 with moderate wear to maybe $400 with light wear.
There were 920,000 of copper-nickel Swiss 5 rappen coins minted in year 1850 in Bern (B). It may currently be worth about $0.15 with heavy wear to around $0.50 with moderate wear to maybe $1.50 with light wear.
Collector value of each coin depends on date, mint mark (if any), number minted and condition of a coin, including amount of wear, any dents, scratches or cleaning as well as collector demand for it.
You might also try your library for a copy of the Standard Catalog of World Coins for pictures, value estimates and lots more interesting info. You might find similar pieces on Ebay.com for comparison.