I'd say learning Spanish (Latin) is far easier than learning English (Germanic) which is filled with silent letters, words with more than a single meaning, combinations of letters that produce unexpected sounds, etc..
Very true. For example, Spanish doesn't have model verbs, which can be very confusing for speakers of Romance languages. For example, there is no literal translation of will or would, etc. Plus Spanish pronunciation is phonetic and therefore more consistent. Think of how you would explain the difference in pronunciation of through and though, or hare, hair, hard, heard, hear, pair, par, pear, far, fair, fir, fire, fare, fear, feel. Although, like English, Spanish can be slurred, and syllables dropped to say things quicker, in general, words don't change as much they do in spoken English when said in a sentence. Just say to yourself "I will ask her". Then think of how you'd say it to a foreigner with limited English and then to a native speaker. To a native speaker, you'd say what say sounds more like Alaska.
And as for Argentinian Spanish being harder, well, it's more that it's just different. It's more common, for example, to use vos for you, rather than tu or usted, which actually was the original Castilian Spanish for tu, vosotros being the plural. A bit like going to an English speaking country and hearing people say thou. Pronunciation is probably the hardest thing, for example, calle becomes more like cache, etc.
But to be honest, some would say that true Castilian Spanish is what's spoken in the Castile region of Spain now, or even the Spanish that's spoken in Spain, so that would mean using vosotros, ceceos and pronouncing your S's like Sean Connery. But does that make it any better than SA Spanish. I don't think so. I don't think anyone with any sense would try and argue that one form of Spanish were better than another.
But remember unlike English, Spanish has the RAE to monitor the language and suggest good practice. In English, there is no such institute, so it makes it that bit harder to suggest whose English grammatical/spelling rules are correct and whose rules aren't. In Spanish, the RAE will tell you. You can disagree with them and it may not be the Spanish spoken on the street, but it's there to protect the Spanish language, offering consistency and clarity. English has no such equivalent. A good linguist could give you much better info than me, but certainly in terms of budget schools and learning clear Castilian Spanish, the Andean countries are hard to beat and the cities of Arequipa and Quito the most popular and cheapest to live in.